Other degenerative diseases of nervous system, not elsewhere classified (G31) ICD-10-CM

Rare leukoencephalopathy with infantile-onset accumulation of Rosenthal fibers in the subpial, periventricular, and subependymal zones of the brain. Rosenthal fibers are GLIAL FIBRILLARY ACIDIC PROTEIN aggregates found in ASTROCYTES. Juvenile- and adult-onset types show progressive atrophy of the lower brainstem instead. De novo mutations in the GFAP gene are associated with the disease with propensity for paternal inheritance.

A rare genetic syndrome with an autosomal recessive pattern of inheritance. It is caused by a mutation in the gene for the mitochondrial DNA polymerase POLG. Clinical signs are usually not present at birth but develop within the first two years of life and include hypoglycemia from underlying liver dysfunction, failure to thrive, spasticity, myoclonus and seizures. The clinical course follows a progression of neurologic disability and hepatic failure. The prognosis is poor with survival outside the first decade unlikely.

Rare progressive neurological disorder characterized by Parkinsonism, cortical atrophy of multiple areas of the brain including the cerebral cortex and the basal ganglia, cognitive dysfunction and eye movement abnormalities.

The most common clinical form of FRONTOTEMPORAL LOBAR DEGENERATION, this dementia presents with personality and behavioral changes often associated with disinhibition, apathy, and lack of insight.

A group of metabolic disorders primarily of infancy characterized by the subacute onset of psychomotor retardation, hypotonia, ataxia, weakness, vision loss, eye movement abnormalities, seizures, dysphagia, and lactic acidosis. Pathological features include spongy degeneration of the neuropile of the basal ganglia, thalamus, brain stem, and spinal cord. Patterns of inheritance include X-linked recessive, autosomal recessive, and mitochondrial. Leigh disease has been associated with mutations in genes for the PYRUVATE DEHYDROGENASE COMPLEX; CYTOCHROME-C OXIDASE; ATP synthase subunit 6; and subunits of mitochondrial complex I. (From Menkes, Textbook of Child Neurology, 5th ed, p850).

A group of rare genetic neurodegenerative disorders that affect infants and children. These disorders are characterized by metabolic abnormalities in the development of the myelin sheaths in the white matter. Clinical signs and symptoms include developmental delays, mental retardation, dementia, seizures, loss of motor skills, and muscle weakness. Representative examples include metachromatic leukodystrophy, Krabbe disease, Canavan disease, and Alexander disease.

A rare form of DEMENTIA that is sometimes familial. Clinical features include APHASIA; APRAXIA; CONFUSION; ANOMIA; memory loss; and personality deterioration. This pattern is consistent with the pathologic findings of circumscribed atrophy of the poles of the FRONTAL LOBE and TEMPORAL LOBE. Neuronal loss is maximal in the HIPPOCAMPUS, entorhinal cortex, and AMYGDALA. Some ballooned cortical neurons contain argentophylic (Pick) bodies. (From Brain Pathol 1998 Apr;8(2):339-54; Adams et al., Principles of Neurology, 6th ed, pp1057-9)

Of the 17 codes in this range, 14 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.

The range classifies other degenerative diseases of nervous system, not elsewhere classified. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.